// Emacs style mode select   -*- C++ -*- 
//-----------------------------------------------------------------------------
//
// $Id:$
//
// Copyright (C) 1993-1996 by id Software, Inc.
//
// This source is available for distribution and/or modification
// only under the terms of the DOOM Source Code License as
// published by id Software. All rights reserved.
//
// The source is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
// for more details.
//
// $Log:$
//
// DESCRIPTION:
//      Handles WAD file header, directory, lump I/O.
//
//-----------------------------------------------------------------------------


static const char
rcsid[] = "$Id: w_wad.c,v 1.5 1997/02/03 16:47:57 b1 Exp $";


#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>

#include "m_swap.h"
#include "doomtype.h"
#include "i_system.h"
#include "z_zone.h"
#include "w_wad.h"

#include <malloc.h>


extern char *main_file;

size_t FileSize(FILE *handle); 

//int _stdcall read_file (char *name, void *buff,
//                        size_t offset, size_t count, size_t *reads);



//
// GLOBALS
//

// Location of each lump on disk.
lumpinfo_t*             lumpinfo;               
int                     numlumps;

void**                  lumpcache;

void
ExtractFileBase
( char*         path,
  char*         dest )
{
    char*       src;
    int         length;

    src = path + strlen(path) - 1;
    
    // back up until a \ or the start
    while (src != path
           && *(src-1) != '\\'
           && *(src-1) != '/')
    {
        src--;
    }
    
    // copy up to eight characters
    memset (dest,0,8);
    length = 0;
    
    while (*src && *src != '.')
    {
        if (++length == 9)
            I_Error ("Filename base of %s >8 chars",path);

        *dest++ = toupper((int)*src++);
    }
}





//
// LUMP BASED ROUTINES.
//

//
// W_AddFile
// All files are optional, but at least one file must be
//  found (PWAD, if all required lumps are present).
// Files with a .wad extension are wadlink files
//  with multiple lumps.
// Other files are single lumps with the base filename
//  for the lump name.
//
// If filename starts with a tilde, the file is handled
//  specially to allow map reloads.
// But: the reload feature is a fragile hack...


int             reloadlump;
char*   reloadname;


void W_AddFile (char *filename)
{
    wadinfo_t           header;
    lumpinfo_t*         lump_p;
    unsigned            i;
    FILE               *handle;
    int                 length;
    int                 startlump;
    filelump_t*         fileinfo;
    filelump_t          singleinfo;
    int                 storehandle;
    int err;
    size_t bytes; 
    
    // open the file and add to directory

    // handle reload indicator.
    if (filename[0] == '~')
    {
        filename++;
        reloadname = filename;
        reloadlump = numlumps;
    }

    printf("open file %s\n\r",filename);
                
    if ( (handle = fopen (filename,"rb")) == NULL)
    {
       printf (" couldn't open %s\n",filename);
       return;
    }

    printf (" adding %s\n\r",filename);
    startlump = numlumps;
        
    if (strnicmp (filename+strlen(filename)-3 , "wad", 3 ) )
    {
        // single lump file
        fileinfo = &singleinfo;
        singleinfo.filepos = 0;
        singleinfo.size = FileSize(handle);
        ExtractFileBase (filename, singleinfo.name);
        numlumps++;
    }
    else 
    {
         //WAD file
        fread (&header, 1, sizeof(header), handle);

        if (strncmp(header.identification,"IWAD",4))
        {
            printf("No IWAD id\n");
            // Homebrew levels?
            if (strncmp(header.identification,"PWAD",4))
            {
                I_Error ("Wad file %s doesn't have IWAD "
                         "or PWAD id\n", filename);
            }
            printf("WAD magic OK\n");
            // ???modifiedgame = true;          
        }
        header.numlumps = LONG(header.numlumps);

        header.infotableofs = LONG(header.infotableofs);

        length = header.numlumps*sizeof(filelump_t);

        fileinfo = alloca(length);
        fseek (handle, header.infotableofs, SEEK_SET);
        fread (fileinfo, 1, length, handle);
        numlumps += header.numlumps;
    }

    
    // Fill in lumpinfo
    lumpinfo = realloc (lumpinfo, numlumps*sizeof(lumpinfo_t));

    if (!lumpinfo)
        I_Error ("Couldn't realloc lumpinfo");

    lump_p = &lumpinfo[startlump];
        
    storehandle = reloadname ? -1 : (int)handle;
        
    for (i=startlump ; i<numlumps ; i++,lump_p++, fileinfo++)
    {
        lump_p->handle = storehandle;
        lump_p->position = LONG(fileinfo->filepos);
        lump_p->size = LONG(fileinfo->size);
        strncpy (lump_p->name, fileinfo->name, 8);
    }
        
    if (reloadname)
        fclose (handle);
}




//
// W_Reload
// Flushes any of the reloadable lumps in memory
//  and reloads the directory.
//
void W_Reload (void)
{
    wadinfo_t           header;
    int                 lumpcount;
    lumpinfo_t*         lump_p;
    unsigned            i;
    FILE                *handle;
    int                 length;
    filelump_t*         fileinfo;
        
    if (!reloadname)
        return;
                
    if ( (handle = fopen (reloadname,"rb")) == NULL)
        I_Error ("W_Reload: couldn't open %s",reloadname);

    fread (&header, 1, sizeof(header), handle);
    
    lumpcount = LONG(header.numlumps);
    header.infotableofs = LONG(header.infotableofs);
    length = lumpcount*sizeof(filelump_t);
    fileinfo = malloc (length);
    fseek (handle, header.infotableofs, SEEK_SET);
    fread (fileinfo, 1, length, handle);
    
    // Fill in lumpinfo
    lump_p = &lumpinfo[reloadlump];
        
    for (i=reloadlump ;
         i<reloadlump+lumpcount ;
         i++,lump_p++, fileinfo++)
    {
        if (lumpcache[i])
            Z_Free (lumpcache[i]);

        lump_p->position = LONG(fileinfo->filepos);
        lump_p->size = LONG(fileinfo->size);
    }
        
    fclose (handle);
}

//
// W_InitMultipleFiles
// Pass a null terminated list of files to use.
// All files are optional, but at least one file
//  must be found.
// Files with a .wad extension are idlink files
//  with multiple lumps.
// Other files are single lumps with the base filename
//  for the lump name.
// Lump names can appear multiple times.
// The name searcher looks backwards, so a later file
//  does override all earlier ones.
//
void W_InitMultipleFiles (char** filenames)
{       
    int         size;
    
    // open all the files, load headers, and count lumps
    numlumps = 0;

    // will be realloced as lumps are added
    lumpinfo = malloc(16384);       

    for ( ; *filenames ; filenames++)
        W_AddFile (*filenames);

    if (!numlumps)
        I_Error ("W_InitFiles: no files found");
    
    // set up caching
    size = numlumps * sizeof(*lumpcache);
    lumpcache = malloc (size);
    
    if (!lumpcache)
        I_Error ("Couldn't allocate lumpcache");

    memset (lumpcache,0, size);
}




//
// W_InitFile
// Just initialize from a single file.
//
void W_InitFile (char* filename)
{
    char*       names[2];

    names[0] = filename;
    names[1] = NULL;
    W_InitMultipleFiles (names);
}



//
// W_NumLumps
//
int W_NumLumps (void)
{
    return numlumps;
}



//
// W_CheckNumForName
// Returns -1 if name not found.
//

int W_CheckNumForName (char* name)
{
    union {
        char    s[9];
        int     x[2];
        
    } name8;
    
    int         v1;
    int         v2;
    lumpinfo_t* lump_p;

    // make the name into two integers for easy compares
    strncpy (name8.s,name,8);

    // in case the name was a fill 8 chars
    name8.s[8] = 0;

    // case insensitive
    strupr (name8.s);           

    v1 = name8.x[0];
    v2 = name8.x[1];


    // scan backwards so patch lump files take precedence
    lump_p = lumpinfo + numlumps;

    while (lump_p-- != lumpinfo)
    {
        if ( *(int *)lump_p->name == v1
             && *(int *)&lump_p->name[4] == v2)
        {
            return lump_p - lumpinfo;
        }
    }

    // TFB. Not found.
    return -1;
}




//
// W_GetNumForName
// Calls W_CheckNumForName, but bombs out if not found.
//
int W_GetNumForName (char* name)
{
    int i;

    i = W_CheckNumForName (name);
    
    if (i == -1)
      I_Error ("W_GetNumForName: %s not found!", name);
      
    return i;
}


//
// W_LumpLength
// Returns the buffer size needed to load the given lump.
//
int W_LumpLength (int lump)
{
    if (lump >= numlumps)
        I_Error ("W_LumpLength: %i >= numlumps",lump);

    return lumpinfo[lump].size;
}



//
// W_ReadLump
// Loads the lump into the given buffer,
//  which must be >= W_LumpLength().
//
void
W_ReadLump
( int           lump,
  void*         dest )
{
    int         c;
    lumpinfo_t* l;
    FILE        *handle;
    size_t bytes;
        
    if (lump >= numlumps)
        I_Error ("W_ReadLump: %i >= numlumps",lump);

    l = lumpinfo+lump;
        
    // ??? I_BeginRead ();
        
    if (l->handle == -1)
    {
        // reloadable file, so use open / read / close
        if ( (handle = fopen (reloadname,"rb")) == NULL)
            I_Error ("W_ReadLump: couldn't open %s",reloadname);
    }
    else
        handle = (FILE *)l->handle;
                
    fseek (handle, l->position, SEEK_SET);
    c = fread (dest, 1, l->size, handle);
    if (c < l->size)
        I_Error ("W_ReadLump: only read %i of %i on lump %i",
                 c,l->size,lump);       

    if (l->handle == -1)
        fclose (handle);
                
    // ??? I_EndRead ();
}




//
// W_CacheLumpNum
//
void*
W_CacheLumpNum
( int           lump,
  int           tag )
{
    byte*       ptr;

    if ((unsigned)lump >= (unsigned)numlumps)
        I_Error ("W_CacheLumpNum: %i >= numlumps",lump);
                
    if (!lumpcache[lump])
    {
        // read the lump in
        
        //printf ("cache miss on lump %i\n",lump);
        ptr = Z_Malloc (W_LumpLength (lump), tag, &lumpcache[lump]);
        W_ReadLump (lump, lumpcache[lump]);
    }
    else
    {
        //printf ("cache hit on lump %i\n",lump);
        Z_ChangeTag (lumpcache[lump],tag);
    }
        
    return lumpcache[lump];
}



//
// W_CacheLumpName
//
void*
W_CacheLumpName
( char*         name,
  int           tag )
{
    return W_CacheLumpNum (W_GetNumForName(name), tag);
}

#if 0

//
// W_Profile
//
int             info[2500][10];
int             profilecount;

void W_Profile (void)
{
    int         i;
    memblock_t* block;
    void*       ptr;
    char        ch;
    FILE*       f;
    int         j;
    char        name[9];
        
        
    for (i=0 ; i<numlumps ; i++)
    {   
        ptr = lumpcache[i];
        if (!ptr)
        {
            ch = ' ';
            continue;
        }
        else
        {
            block = (memblock_t *) ( (byte *)ptr - sizeof(memblock_t));
            if (block->tag < PU_PURGELEVEL)
                ch = 'S';
            else
                ch = 'P';
        }
        info[i][profilecount] = ch;
    }
    profilecount++;
        
    f = fopen ("waddump.txt","w");
    name[8] = 0;

    for (i=0 ; i<numlumps ; i++)
    {
        memcpy (name,lumpinfo[i].name,8);

        for (j=0 ; j<8 ; j++)
            if (!name[j])
                break;

        for ( ; j<8 ; j++)
            name[j] = ' ';

        //printf ("%s ",name);

        for (j=0 ; j<profilecount ; j++)
            fprintf (f,"    %c",info[i][j]);

        //printf ("\n");
    }
    fclose (f);
}

#endif







